Euston-King's Cross-St. Pancras looks like it will be one crazy interchange station.

The River Lea is included along with the Thames (not sure why)

The Beckton curve is shown on the map

I doubt a map like this would ever be used by TFL as it's simply too complicated. However, I think Brian has done an incredible job highlighting the issues that TFL will (hopefully) soon have to address. Mainly how much more can you add to the current map before it becomes unreadable.

The genius of Beck's 1933 Tube Map was that it made everything simple. While the map above uses Beck's techniques of straight, vertical and 45 degree diagonal lines, there are simply too many of them and geographical accuracy is further sacrificed. When all these services do open, it will take another genius like Beck to help use navigate our way around them. Until then, this is a great attempt in my opinion.